Use of fluid aspiration/dispensing tip as a microcentrifuge tube

ABSTRACT

A fluid aspirating/dispensing member includes a sample cavity for sample acquisition and a sealable cavity that, once sealed, permits the separation of particles from the remainder of a fluid sample within the sample cavity after centrifugation or other separation means. The fluid aspirating/dispensing members, either individually or as part of an array, increase the efficiency of sample processing before analysis by a clinical analyzer.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. Ser. No.12/174,336, filed on Jul. 16, 2008, the entire contents of which areincorporated by reference.

FIELD OF THE APPLICATION

This application relates to an apparatus and a method for samplecollection and centrifugation within a single, disposable fluidaspirating/dispensing member.

BACKGROUND OF THE INVENTION

Combinational clinical analyzers containing both “wet” and “dry”chemistry platforms in a single apparatus for the testing of biologicalsamples, such as whole blood serum, are now widely used in most modernhealth care facilities.

So-called “dry” chemistry systems commonly include a sample supply, anumber of sample containers, a metering/transport mechanism, and anincubator having a plurality of test read stations as described, forexample, in U.S. Pat. No. 3,992,158, the contents of which are herebyincorporated herein by reference in its entirety. A typical protocolstarts with the aspiration of a known quantity of a sample into a fluidaspirating/dispensing member. An aliquot of the sample is then dispensedonto a dry slide element which is then loaded into an incubator. Afterappropriate incubation, the amount or presence of at least one analytein the sample is determined using, for example, an electrometer,reflectometer or other suitable testing devices.

So-called “wet” chemistry systems on the other hand, use a reactionvessel, such as a cuvette, which receives predetermined volumetricquantities of sample, reagent, and other fluids that are appropriatelymetered into a reaction vessel in order to perform an assay(s). The“wet” chemistry system commonly includes a metering mechanism totransport a patient sample fluid from a sample supply to the reactionvessel. After a pre-determined incubation period during which one ormore reactions occur, a measuring device, such as an optical measuringdevice is used to pass a beam of light through the reaction vessel andsample. Assays typically used in ‘wet’ chemistry systems include, butare not limited to, spectrophotometric absorbance assays such as endpoint reaction analysis and rate of reaction analysis, turbidimetricassays, nephelometric assays, radiative energy attenuation assays (suchas those described in U.S. Pat. Nos. 4,496,293 and 4,743,561, thecontents of which are hereby incorporated herein by reference in theirentirety), ion capture assays, color, metric assays, and fluorometricassays, and immunoassays, all of which are well known in the art.

Integration of wet/dry chemistry capabilities into clinical analyzersreduces experimental error, improves work flow and limits the need forhuman intervention thereby reducing the risk of contamination of labpersonnel with human pathogens. One example of a commercially availablecombination clinical analyzer employing both wet and dry chemistrysystems is the Vitros 5,1 FS Chemistry System, which is described infurther detail in U.S. Pat. No. 7,250,303 and U.S. Patent PublicationNo. US 2003/0026733 (each assigned to OrthoClinical Diagnostics,Rochester, N.Y.), the contents of which are incorporated herein byreference in its entirety.

Despite the progress that has been made, these systems still requirethat patient samples be first processed to remove particulate componentsbefore presentation to a clinical analyzer. This processing step remainscumbersome, time consuming and limits the overall efficiency of theseanalyzers.

Information relevant to attempts to address this problem can be found inU.S. Pat. Nos. D453,573; 4,933,291; 5,384,239; 5,722,553; 5,753,186;6,001,310; 6,334,842; 6,601,725; 6,622,882; 7,064,823; the publishedU.S. Publication Numbers US 2001/0019842; US 2005/0204832; US2005/0208676; US 2007/0003443, US 2007/0017927; International PCTapplication PCT/AU1992/000236 and European Patent No. EP743095. Each oneof these references suffers, however, from one or more of the followingdisadvantages: the references fail to remedy the inefficient processingof patient samples prior to clinical analysis and also fail to describea fluid aspirating/dispensing member that permits both sample collectionand centrifugation.

For the foregoing reasons, there is an unmet need in the field toimprove the efficiency of sample processing prior to analysis byclinical analyzers.

SUMMARY OF THE APPLICATION

The invention pertains to a fluid aspirating/dispensing member having asealable end that can be used for both sample collection andcentrifugation. Methods are described for performing sample collectionand centrifugation using either individual fluid members or platescomprising a plurality of fluid aspirating/dispensing members.

According to one version, a fluid aspirating/dispensing member isdescribed that comprises a first port, a second port, opposite the firstport, and a cap. The cap is configured to releasably close the firstport when attached thereto. The internal volume of the fluidaspirating/dispensing member comprises a sample cavity between the firstand second ports; and a sealable cavity between the second port and thesample cavity. The sealing of the sealable cavity seals the second portto create a container that is configured to retain a fluid sample in thesample cavity and to permit the separation of particles suspended in thesample from the remainder of the sample.

According to another aspect, the fluid aspirating/dispensing member isconfigured to be placed within a testing apparatus capable of separatingparticles from the remainder of the fluid sample. The apparatus may be aclinical analyzer. The separation of the particles from the remainder ofthe sample can result, for example, from centrifugation.

In one aspect, the walls of the sample cavity are tapered, whereas thewalls of the sealable cavity can be parallel with respect to thevertical axis of the fluid aspirating/dispensing member.

The sealable cavity of the fluid aspirating/dispensing member can beheat-sealable, less than lcm long, with walls that are less than 2 mmapart and parallel to the vertical axis of the aspirating/dispensingmember.

In one aspect, the cap is removably attached to theaspirating/dispensing member.

The aspirating/dispensing member can allow for optical or visual testingof a sample, which can be a cell suspension or blood. Particles withinthe sample can be red blood cells.

The aspirating/dispensing member can further contain a separationbarrier or reagents for agglutination within the internal volume of eachmember.

According to another version, a fluid aspirating/dispensing plate isdescribed that comprises an array of fluid aspirating/dispensing membersattached to a solid support. Each of the aspirating/dispensing memberscomprises a first port and a second port, opposite the first port. Theinternal volume of each fluid aspirating/dispensing member comprises asample cavity between the first and second ports; and a sealable cavitybetween the second port and the sample cavity. The sealing of thesealable cavity of each of the fluid aspirating/dispensing memberscreates a plurality of containers that are configured to retain a fluidsample in the sample cavity and permit the separation of particlessuspended in the sample from the remainder of the sample.

In one aspect, the solid support is planar that can include a means forsupporting the fluid aspirating/dispensing members. The fluidaspirating/dispensing plate can have 96 fluid aspirating/dispensingmembers.

In another aspect, the fluid aspirating/dispensing members arereversibly attached to the solid support.

In another version, the fluid aspirating/dispensing plate is configuredto be placed within a testing apparatus capable of separating particlesfrom the remainder of the sample of each the fluid aspirating/dispensingmember. This testing apparatus can be a clinical analyzer.

The separation of the particles from the remainder of the sample canresult from separation by centrifugation.

The sealable cavity of the fluid aspirating/dispensing plate can be aheat-sealable cavity.

In another version, the fluid aspirating/dispensing plate has a coverthat is configured to close each of the first ports when the cover isplaced on the first ports of the fluid aspirating/dispensing plate.

In one aspect, the fluid aspirating/dispensing members of the plateallow for optical or visual testing of a sample within the internalvolume of each member.

In another aspect, the array of aspirating/dispensing members on theplate align with the wells of a microtiter plate. Each well of themicrotiter plate can retain a sample that is different from each of theother wells in the plate, wherein the sample can be a cell suspension orblood. Particles within the sample can be cells.

In yet another aspect, the aspirating/dispensing members on the platecan contain a separation barrier or reagents for agglutination withinthe internal volume of each member.

According to another embodiment, a method is described for separatingparticles in a fluid sample, the method comprising the steps of (a)loading a fluid aspirating/dispensing member into an apparatus, themember comprising a first port, a second port and a sample cavity influid communication with the first and second ports, (b) aspirating asample into the sample cavity through the second port of the fluidaspirating/dispensing member, (c) sealing the second port of the fluidaspirating/dispensing member to create a fluid container; (d) closingthe first port using a cap sized to releasably engage and cover thefirst port; and (e) separating particles in the sample from theremainder of the sample, wherein the separated particles and sample areretained within the sample cavity of the fluid aspirating/dispensingmember for detection of the particles or sample.

The apparatus can be a clinical analyzer. The separating step can beperformed, for example, by centrifugation.

According to one aspect, the loading step requires the attachment of thefluid aspirating/dispensing member to a proboscis of a meteringmechanism of the apparatus.

In another aspect, the fluid aspirating/dispensing member is a meteringtip.

In one aspect, the sealing step is performed by heat sealing the secondport of the fluid aspirating/dispensing member.

According to yet another embodiment, a method is described forseparating particles in a plurality of fluid samples, the methodcomprising the steps of (a) loading a fluid aspirating/dispensing plateinto an apparatus, wherein the plate comprises a plurality of fluidaspirating/dispensing members, each of the members comprising a firstport, a second port and a sample cavity in fluid communication with eachof the first and second ports, (b) aspirating a plurality of samplesinto the sample cavities through the second ports of each of the fluidaspirating/dispensing members, (c) sealing the second ports of each ofthe fluid aspirating/dispensing members to create a plurality of fluidcontainers and (d) separating particles in the sample from the remainderof the sample in each of the containers, wherein the particles andsample are retained within the sample cavity of each of the fluidaspirating/dispensing members for detection of the particles or sample.

In one aspect, the apparatus is a clinical analyzer.

The separating step can be performed by centrifugation.

In one aspect the loading step requires the attachment of the fluidaspirating/dispensing plate to a plurality of proboscis of a meteringmechanism of the apparatus.

In another aspect, the fluid aspirating/dispensing members are meteringtips.

According to another embodiment, after the aspirating step, the firstports of each of the fluid aspirating/dispensing members are closed by alid that is configured to close the first ports of each of the fluidaspirating/dispensing members when it is placed on the first ports ofthe fluid aspirating/dispensing members.

The sealing step can be performed by heat sealing the second ports ofeach of the fluid aspirating/dispensing members.

The previously described embodiments have many advantages, including theability to perform sample collection and particle separation usingeither individual disposable fluid aspirating/dispensing members or afluid aspirating/dispensing plate comprising a plurality of fluidaspirating/dispensing members. The methods described herein reducehandling errors as well as the time spent for sample processing beforeanalysis by clinical analyzers. Sample processing using the hereindescribed fluid aspirating/dispensing member is therefore faster thanconventional methods known in the art.

It should be understood that this application is not limited to theembodiments disclosed in this Summary, and it is intended to covermodifications and variations that are within the scope of those ofsufficient skill in the field, and as defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a cross-sectional view of a fluid aspirating/dispensingmember made in accordance with one embodiment;

FIG. 2 illustrates the movement of the cap of the fluidaspirating/dispensing member of FIG. 1;

FIGS. 3A-3G depict sequential cross-section views of the fluidaspirating/dispensing member of FIG. 1 representing a method of samplecollection and centrifugation in accordance with a second embodiment;

FIG. 4A depicts a view of a fluid aspirating/dispensing plate comprisingan array of fluid aspirating/dispensing members in accordance with athird embodiment;

FIG. 4B depicts a cross-sectional view of a row of fluidaspirating/dispensing members of the plate of FIG. 4A;

FIG. 5 illustrates the alignment of the array of fluidaspirating/dispensing members of FIG. 4A with a microtiter plate;

FIGS. 6A-61 depict sequential cross-section views of the array of fluidaspirating/dispensing members of FIG. 4A representing a method of samplecollection and centrifugation in accordance with a fourth embodiment.

DETAILED DESCRIPTION

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as is commonly understood by one of skill in theart. The following definitions are provided to help interpret thedisclosure and claims of this application. In the event a definition inthis section is not consistent with definitions elsewhere, thedefinition set forth in this section will control.

As used herein, “combinational” analyzer refers to a clinical analyzerthat includes at least two chemistry systems that can encompass anycombination of “dry” and/or “wet” chemistry systems.

As used herein, a “clinical analyzer” refers to any apparatus capable ofanalyzing clinical samples including, but not limited to,immunodiagnostic analyzers as well as analyzers for the automated “wet”and/or “dry” chemistry analysis of clinical samples. “Wet” chemistryplatforms typically include a microprocessor controlling an automatedfluid handling system that aspirates and dispenses one or more samplesand/or reagents into a reaction vessel, at least one sample reservoir,optionally at least one reagent reservoir, at least one incubator and atleast one detector, such as a spectrophotometer. Typical analyzers foruse with the fluid aspirating/dispensing member of this application aredescribed in further detail in U.S. Pat. Nos. 6,096,561, 7,282,372 and7,250,303, all of which are incorporated herein by reference in theirentireties. In a preferred embodiment, the clinical analyzer used hereinrefers to commercially available analyzers such as the VITROS 5,1 FSChemistry System manufactured by Ortho-Clinical Diagnostics, Inc.

An element is in “fluid communication” with another element when a fluidis able to travel from one element to the other such as via capillaryaction and/or gravity. The elements may be in direct contact, but do notneed to be in direct contact; i.e., other elements through which saidfluid can pass may be intervening. An element is “not in fluidcommunication” with another element when a fluid is not able to travelfrom one element to the other via capillary action and/or gravity.Typically, the elements are physically separated, i.e. spaced apart.

As used herein, a “fluid aspirating/dispensing member” is a device suchas a metering tip containing one or more internal cavities in fluidcommunication with two or more sealable apertures that is used for bothsample collection and particle separation as described in U.S. Pat. No.6,797,518, the contents of which are hereby incorporated by referenceherein in its entirety. In one embodiment, the particle separationoccurs as a result of centrifugation. A fluid aspirating/dispensingmember typically performs the aspiration or dispensing of a volumetricamount of a sample within a clinical analyzer. In one embodiment, thefluid aspirating/dispensing member is composed of a molded, solidmaterial that can be centrifuged without deformation of the internalcavities. In another embodiment, the material does not promote theadhesion of a biological sample to the internal walls of the fluidaspirating/dispensing member. In another embodiment the fluidaspirating/dispensing member is made out of a plastic material typicallyby extrusion blow molding. The fluid aspirating/dispensing member can bemade from a thermoplastic material preferably having a translucent ortransparent characteristic that allows optical testing to be performedupon the fluid contents after aspiration therein. In one embodiment, thefluid aspirating/dispensing member is made of a moldable plastic such aspolypropylene or polyethylene. In another embodiment, the fluidaspirating/dispensing member is made of a homopolymer or copolymer suchas a polyallomer, wherein one of the monomers is propylene. In yetanother embodiment, the fluid aspirating/dispensing member is made ofpolyethylene terephthalate.

As used herein, a “fluid aspirating/dispensing plate” refers to an arrayof multiple fluid aspirating/dispensing members attached to a solidsupport. Each fluid aspirating/dispensing member comprises one or moreinternal cavities in fluid communication with two or more sealableapertures for both sample collection and particle separation. A fluidaspirating/dispensing plate is typically used for the aspiration ordispensing of a volumetric amount of one or more samples within aclinical analyzer. In one embodiment, the support is planar andrectangular or square in shape, although the fluid aspirating/dispensingplate described herein may have any shape. In another embodiment, thefluid aspirating/dispensing members on the fluid aspirating/dispensingplate are arranged in rows, each row having the same number of fluidaspirating/dispensing members. In another embodiment, the fluidaspirating/dispensing plate comprises a support for the fluidaspirating/dispensing members. A person of skill in the art willrecognize that the support can be engineered to facilitatecentrifugation and robotic handling in a clinical analyzer. In oneembodiment, the fluid aspirating/dispensing members are reversiblyaffixed to the solid support. In another embodiment, the multiple fluidaspirating/dispensing members are arrayed on a fluidaspirating/dispensing plate in such a manner so as to align with thewells of a microtiter plate. In yet another embodiment, the plate has aplurality of locations for the reversible attachment of one, two, five,ten, 25, 50, 75, 100 or more fluid aspirating/dispensing members. Eachlocation on the plate may or may not be filled with a fluidaspirating/dispensing member.

As used herein, “separation of the particles from the remainder of thesample” refers to any procedure that permits the separation of theliquid phase of a sample from its solid particulate phase. In oneembodiment, the “separation of the particles from the remainder of thesample” refers to the partial or complete separation of the solidparticulate phase of a sample from its liquid phase within the samplecavity of the fluid aspirating/dispensing member after the sealing ofthe fluid aspirating/dispensing member. In another embodiment, theseparation occurs as a consequence of centrifugation. In yet anotherembodiment, the separation results from a magnetic field acting onmagnetic particles that have been added to a sample.

As used herein, the term “sealable, cavity” refers to a region of thefluid aspirating/dispensing member, located between the sample cavityand the bottom end of the aspirating/dispensing member, which can besealed, for example, by heat sealing or as a result of the applicationof a sealant as defined herein. As a consequence of sealing, the samplecavity is no longer in fluid communication with theaspirating/dispensing end of the fluid aspirating/dispensing member thuscreating a fluid container for particle separation. In one embodiment,the sealable cavity is made of a thermoplastic melt-fusible material. Inanother embodiment the thermoplastic melt-fusible material is apolyallomer or similar thermoplastic material suitable for heat sealingas known by a person of skill in the art.

As used herein, “heat sealing” refers to the application of sufficientheat and pressure to the walls of the sealable cavity of the fluidaspirating/dispensing member to cause the walls to fuse together.Subsequent curing i.e. the hardening and solidification of the fusedthermoplastic walls creates a pressure-resistant sealing of the sealablecavity that prohibits fluid communication between the sample cavity andthe sealable aspirating/dispensing end of the fluidaspirating/dispensing member. A more detailed description of heatsealing can be found in U.S. Pat. No. 3,929,943, the contents of whichis hereby incorporated herein in its entirety. In another embodiment,heat sealing is applied to the sealable cavities of a plurality of fluidaspirating/dispensing members arrayed on a fluid aspirating/dispensingplate. For example, the aspirating/dispensing ends of the array of fluidaspirating/dispensing members can be aligned and inserted into an arrayof metallic molding cups that are heated to a temperature that promotesthe melting and fusion of the walls of the sealable cavities placedtherein.

As used herein, “sealing” refers to the permanent closing of theaspirating/dispensing end of a fluid aspirating/dispensing member. Inone embodiment, sealing refers to heat sealing. In another embodiment,sealing refers to the application of a sealant, for example, a plasticor adhesive, that hermetically plugs the aspirating/dispensing end of afluid aspirating/dispensing member. In another example, the sealant maybe a bottom cap, such as a bottom screw cap, that hermetically closesthe aspirating/dispensing end of a fluid aspirating/dispensing member.

As used herein, a “sealant” shall mean any composition such as anadhesive that can be used to form a connecting bond between the walls ofthe sealable cavity of the fluid aspirating/dispensing member describedherein. In one embodiment the sealant is UV curable. In anotherembodiment, the sealant cures at room temperature.

As used herein, the term “polyallomer” refers to any thermoplasticmaterial that produces copolymers of the 1-olefins exhibiting a degreeof crystallinity normally associated only with homopolymers. In oneembodiment, the polyallomer is a random block copolymer of propylene andethylene. In another embodiment, the polyallomer is a readily fusibleplastic material sold by Eastman Chemical Co. under the trade name“Tenite® Polyallomer.”

As used herein, the term “cavity” refers to any three-dimensionalenclosure within the described fluid aspirating/dispensing member. In anexemplary embodiment, one or more cavities are in fluid communicationwith each other.

The term “plurality,” as used herein, refers to a quantity of two ormore.

As used herein, “particles” may be cells, for example, bacteria or redblood cells or white blood cells found in a sample. In anotherembodiment, particles may be microscopic solids that are added to asample prior to sample processing. These particles may be inert solidsin the form of beads, beaded gels or microspheres, although they mayhave any shape. Further examples of particles include, but are notlimited to, plastic particles, ceramic particles, carbon particles,polystyrene microbeads, latex beads, glass beads, magnetic beads, hollowglass spheres, metal particles, particles of complex compositions,microfabricated or micromachined particles. Inert particles may becomprised of any suitable material, such as glass or ceramics, organicmaterials such as carbon or plastic and/or one or more polymers, suchas, for example, nylon, polytetrafluoroethylene (TEFLON™) orstyrene-divinylbenzene polymers. The particle size may be from about 0.1micron to 1000 microns. Preferably, the particle size is from about 1 toabout 10 microns. In principle, any ligand may be covalently bound to asolid-phase matrix or particle such as agarose beads (e.g., SepharosePharmacia) using known techniques, for example as described by Heam etal., Methods in Enzymology Vol. 35:102-117 (1987). Generally, the beadsare first activated by a chemical agent, such as glutaraldehyde,carbonyldiimidizole, cyanogen bromide hydroxysuccinimide, tosyl chlorideor the like. The chosen ligand is then covalently attached to the beads,resulting in an extremely stable linkage of the ligand to the support.

As used herein, “cell suspension” refers to a mixture of cells in aliquid typically found in a sample. Cells can be eukaryotic orprokaryotic cells. In one embodiment, the cells are bacteria. In anotherembodiment, the cells are pathogenic bacteria. In a preferredembodiment, the cells are blood cells. In another preferred embodiment,the cells are red blood cells.

As used herein, the term “sample” refers to a material suspected ofcontaining at least one analyte. The sample can be used directly asobtained from the source or following a pretreatment to modify thecharacter of the sample. The sample can be derived from any biologicalsource, such as a physiological fluid, including, blood, plasma, saliva,ocular lens fluid, cerebral spinal fluid, sweat, urine, milk, ascitesfluid, raucous, synovial fluid, peritoneal fluid, amniotic fluid or thelike. The sample can be pretreated before use. For example, whole bloodis typically treated with a polyanion such as heparin and the like toinhibit blood coagulation. In another example, viscous fluids can bediluted. Methods of treatment can also include filtration, distillation,concentration, inactivation of interfering components, and the additionof reagents. Besides physiological fluids, other liquid samples can beused. In addition, a solid material suspected of containing an analytecan be used as the sample. In some instances it may be beneficial tomodify a solid sample to form a liquid medium or to release the analyte.In another embodiment, a sample, as defined herein, is understood toinclude one or more compounds that may be added to the sample before orduring analysis, including, but not limited to, buffers, reagents,peptides, enzymes, ligands, ligand-binding molecules, antibodies,particles, ligand-bound particles, magnetic particles, and the like. Asample, as defined herein, may contain particles as defined above.

The term “analyte,” as used herein, refers to any compound orcomposition or entity to be detected or measured. An analyte can be anyinorganic or organic molecule or cellular component or cell or organismthat is tested for by clinical assays known in the art. Clinical assaysmay test for either the presence or absence of an analyte. In oneembodiment, an analyte has at least one epitope or binding site orligand. In another embodiment, an analyte can be any substance for whichthere exists a naturally occurring binding member or for which a bindingmember can be prepared. In yet another embodiment, an analyte refers toa population of cells, for example, blood cells such as white bloodcells, red blood cells (hematocrit) or platelets. Analytes may alsoinclude, but are not limited to, metabolites, toxins, inorganic ororganic compounds, proteins, peptides, cytokines, chemokines, enzymes,amino acids, lipids, HDL/LDL cholesterol, triglycerides,polysaccharides, blood glucose, nucleic acids, hormones (for example,thyroid stimulating hormone (TSH), Adrenocorticotropic hormone (ACTH),prolactin), steroids (for example, cortisol or testosterone orestrogen), vitamins, electrolytes, drugs, ions (for example, for pHmeasurements), trace metals, microorganisms (bacteria, viruses orparasites and the like), virus particles, metabolites of and antibodiesto any of the above substances. In another embodiment, the analyte is Creactive protein, albumin, amylase, D-dimer, bilirubin, alkalinephosphatase, gamma glutamyl transferase, urea, creatine, serum iron,transferring, prostate specific antigen (PSA), alpha fetoprotein (AFP),beta Human chorionic gonadotrophin (bHCG), alpha 1-antitrypsin (AAT),CA-125 (also CA12.5), carcinoembryonic antigen (CEA), fibrinogen or anyother compound which is typically tested for in a clinical sample. Theterm “analyte” may include any antigenic substances, haptens,antibodies, macromolecules and combinations thereof. In anotherembodiment, the analyte is an enzyme that can be detected by measuringenzyme activity. For example, the testing for creatine kinase, glutamicoxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase(SGPT) activity in blood is widely used as an indicator of liver orheart damage.

As used herein, a “ligand” is any molecule which is capable of bindingto a ligand-binding molecule. In one embodiment, the ligand is anepitope of an antibody. A number of ligands are also known that bindimmunoglobulin molecules and may be covalently coupled to the particlesused in this application, for example Protein A, Protein G, Protein A/Gand KappaLock™ (see also U.S. Pat. No. 5,665,558, the contents of whichare herein incorporated by reference in its entirety). The ligand maybind to the isotype of the antibody which is used or tested for or,alternatively, one may use a bridging antibody, e.g., an IgG antiIgM,for an IgM antibody. Thus, an IgG anti-IgM antibody would be coupled tothe ligand as a “bridge” and an IgM antibody would bind to the IgGanti-IgM antibody.

The term “ligand-binding,” as used herein, refers to a member of abinding pair, i.e., two different molecules wherein one of the moleculesspecifically binds to the second molecule through chemical or physicalmeans. In addition to antigen and antibody binding pair members, otherbinding pairs include, as examples without limitation, biotin andavidin, carbohydrates and lectins, complementary nucleotide sequences,complementary peptide sequences, polysaccharides and lectins, effectorand receptor molecules, enzyme cofactors and enzymes, enzyme inhibitorsand enzymes, a peptide sequence and an antibody specific for thesequence or the entire protein, polymeric acids and bases, dyes andprotein binders, peptides and specific protein binders (e.g.,ribonuclease, S-peptide and ribonuclease S-protein), and the like.Furthermore, binding pairs can include members that are analogs of theoriginal binding member, for example, an analyte-analog or a bindingmember made by recombinant techniques or molecular engineering. If thebinding member is an immunoreactant it can be, for example, a monoclonalor polyclonal antibody, a recombinant protein or recombinant antibody, achimeric antibody, a mixture(s) or fragment(s) of the foregoing, as wellas a preparation of such antibodies, peptides and nucleotides for whichsuitability for use as binding members is well known to those skilled inthe art. A ligand-binding member may be a polypeptide affinity ligand(see, for example, U.S. Pat. No. 6,326,155, the contents of which arehereby incorporated by reference herein in its entirety). In oneembodiment, the ligand-binding member is labeled. The label may beselected from a fluorescent label, a chemiluminescent label or abioluminescent label, an enzyme-antibody construct or other similarsuitable labels known in the art.

As used herein “blood” broadly includes whole blood or any component ofwhole blood, such as red blood cells, white blood cells, plasma orserum.

As used herein, “centrifugation” refers to the rotation of an objectabout an axis of rotation. Samples may be centrifuged in a fixed angleor swing bucket rotor or any other rotor known in the art.

As used herein, “STAT” is a medical term derived from the Latin word “statim” which means immediately. A “STAT lane” therefore refers to theurgent or rush processing of patient samples.

As used herein, “emergency sample” refers to any sample that requiresimmediate processing. Emergency samples typically include those samplescollected in emergency rooms or other urgent care facilities. Forexample, an emergency room sample can be a blood sample taken from apatient in an emergency room.

“Agglutination,” as used herein refers to the clumping of a suspensionof cellular or particulate antigen by a reagent, usually an antibody orother ligand-binding entities (see, for example, U.S. Pat. Nos.4,305,721, 5,650,068 and 5,552,064, the contents of which are herebyincorporated herein by reference in their entirety). In one embodiment,the reagent is Coomb's reagent.

As used herein, “Coomb's reagent” refers to a preparation of antibodies,raised in animals, directed against one of the following humanimmunoglobulin, complement or a specific immunoglobulin e.g. anti-humanIgG for use in the Coomb's test.

As used herein, “detection” refers to the detection of light absorptionor light scattering using a photodetector (see, for example, U.S. Pat.No. 5,256,376 and published U.S. patent application US 2004/0166551, thecontents of which are hereby incorporated herein by reference in theirentirety). In one embodiment, detection refers to the detection ofbioluminescence or chemiluminescence or fluorescence (see, for example,U.S. Pat. No. 6,596,546, the contents of which are hereby incorporatedherein by reference in its entirety).

As used herein, the term “agitating” refers to a force acting on thecontents of a fluid aspirating/dispensing member, for example acentrifugal force or a force induced by a magnetic field.

As used herein, a “metering device,” as used herein, refers to acomponent of a clinical analyzer that can reversibly attach to a fluidaspirating/dispensing member by means of a proboscis. In one embodiment,metering devices, controlled by an on-board computer, coordinate themovement and/or transport of fluid aspirating/dispensing members or afluid aspirating/dispensing plate within a clinical analyzer.

As used herein, the term “proboscis” refers to a component of a clinicalanalyzer that attaches to one or more aspirating/dispensing members,either individually or as part of a fluid aspirating/dispensing plate.In one embodiment, the proboscis is part of a metering mechanism and canbe cylindrical in shape and fits within the proboscis receptacle regionof each of one or more fluid aspirating/dispensing members in such amanner as to insert itself against the internal wall of the proboscisreceptacle region of a fluid aspirating/dispensing member in anair-tight manner (i.e., there is no substantial leak of air between thecylindrical surface of the proboscis and the wall). Once the proboscisis hermetically affixed to the proboscis receptacle region of each ofthe fluid aspirating/dispensing member, the proboscis by means of themetering mechanism, confers either a vacuum or pressure to the internalvolume of each fluid aspirating/dispensing member and thereby drives themovement of a known volume of fluid within the internal cavities of eachfluid aspirating/dispensing member.

As used herein, the term “separation barrier” refers to a waterimmiscible, typically thixotropic, gel-like or bead=like material havinga density intermediate between that found for the light, liquid phaseand the heavy, substantially particulate phases of a sample. Forexample, the separation barrier is typically disposed in the samplecavity of the fluid aspirating/dispensing member which is then filledwith the sample. Upon centrifugation, the sample is gradient separatedinto its two phases and the barrier material migrates to the interfacebetween the phases. Upon completion of centrifugation, the separationbarrier forms a physical and chemical barrier between the separatedphases, thereby preventing any mixing of the phases. Separation barrierscan be, for example, a mixture of silicone fluids and fine hydrophobicsilica powder, a polyester material or a hydrocarbon gel-like materialsuch as a polybutane or any other material known in the art. Thecomposition of separation barrier materials is described in furtherdetail in U.S. Pat. Nos. 4,190,535; 4,101,422; 4,818,418 and 4,147,628,the contents of which are hereby incorporated herein in their entirety.

As used herein, the term “antibody” includes both polyclonal andmonoclonal antibodies; and may be an intact molecule, a fragment thereof(such as Fv, Fd, Fab, Fab′ and F(ab)′ 2 fragments, or multimers oraggregates of intact molecules and/or fragments; and may occur in natureor be produced, e.g., by immunization, synthesis or genetic engineering.The antibody or antigen used herein is dependent upon the antibody orantigen that is being tested. For example, the number of blood groupantigens and thus, antibodies to these antigens that have beenidentified is very large, with more antigens and antibodies continuallybeing determined. The International Society of Blood Transfusion haspublished a non-exclusive list of red cell antigens in Blood GroupTerminology 1990, Vox. Sang. 58:152-169 (1990 and includes, but is notlimited to, antibodies and antigens A, B, D, C, c, Cw, E, e, K, Fya,Fyb, Jka, Jkb, S and s.

With the preceding definitions as noted herein, the followingdescription relates to certain preferred embodiments of the application,and to a particular methodology for the initial processing of patientsamples prior to chemical analysis. As will be readily apparent from thediscussion, the inventive concepts described herein can also be suitablyapplied to other methods that require the efficient processing ofpatient samples. In addition, such terms as “top,” “bottom,” “lateral,”“above,” “below” and the like are also used in order to provide aconvenient frame of reference for use with the accompanying drawings.These terms, unless stated specifically otherwise, however, are notintended to be limiting of the present invention. A novel fluidaspirating/dispensing member is described herein that permits bothsample collection and particle separation by centrifugation or otherseparation means, thereby increasing the efficiency of sample processingbefore analysis by the wet/dry chemistry components of a combinationalclinical analyzer.

According to a first embodiment, FIG. 1 shows a sealable fluidaspirating/dispensing member 100 for sample collection and particleseparation. The fluid aspirating/dispensing member 100 is typicallycomposed of an injection-moldable, preferably transparent, thermoplasticmaterial such as polypropylene, polyallomer, polyethylene terephthalate,co-polymers or blends of polymers or any other suitable inert materialknown in the art. Preferably, the sample being analyzed does not adhereto the walls of the internal volume of the fluid aspirating/dispensingmember 100 wherein these surfaces of the fluid aspirating/dispensingmember 100 may be treated to avoid such adherence of the sample orreagents to the internal surfaces of the fluid aspirating/dispensingmember 100. The internal volume of a fluid aspirating/dispensing member100 may be from about 1 microliter to about 2000 microliters or more. Inone example, the internal volume is from about 1 microliter to about 500microliters. In a preferred embodiment, the fluid aspirating/dispensingmember 100 has an internal volume of about 1 microliter to about 300microliters. The thickness of the wall of a fluid aspirating/dispensingmember 100 is not critical provided it can withstand centrifugationwithout deformation. Typically, the wall has a thickness from about 5 mmto about 0.1 mm, from about 2 mm to about 0.5 mm or from about 1.5 mm toabout 0.75 mm. As shown in FIG. 1, the fluid aspirating/dispensingmember 100 is defined at an upper end by an input port 104 and at alower end by a sealable input port 108. Between input ports 104 and 108is an internal cavity comprising a sample cavity 106 which is in fluidcommunication with input ports 104 and 108. The input port 104 isconfigured to attach hermetically to the proboscis of a meteringmechanism (not shown in this view) for the movement of known volumes ofair from the internal volume of the fluid aspirating/dispensing member100. In one embodiment, the proboscis 320 inserts hermetically throughthe input port 104 into a proboscis receptacle region 112 of the fluidaspirating/dispensing member 100. The sealable input port 108 isconfigured to permit aspiration or dispensing of fluids through theinput port 108 and into the sample cavity 106. The walls of the sealablecavity can be thinner than those of the sample cavity 106 to facilitateheat sealing. In one version, the internal volume of the fluidaspirating/dispensing member 100 may be pre-loaded with reagents thatare required for clinical analysis, for example, reagents for bloodagglutination or blood typing. In another embodiment, the sample cavityof the fluid aspirating/dispensing member 100 contains a separationbarrier as defined herein.

Referring now to FIGS. 1 and 2, the herein described fluidaspirating/dispensing member 100 is shown with an optional cap 114connected to the upper end of the member 100 by means of a tether 116.The tether 116 may be of any length as long as it does not interferewith sample collection or particle separation, i.e., centrifugation. Forexample, the tether 116 may be from about 0.5 cm to about 2 cm in lengthor from about 0.5 cm to about 1 cm in length. By bending the tether 116in the direction 210, the cap 114 can be reversibly inserted into theinput port 104. In one version, the cap 114 is not attached to the fluidaspirating/dispensing member 100 (not shown) and is therefore inserteddirectly into input port 104 before centrifugation. The placement of thecap 114 over input port 104 forms a hermetic seal that prevents fluidsin the sample cavity 106 from escaping through input port 104 duringcentrifugation and/or handling of the fluid aspirating/dispensing member100. In another version, the fluid aspirating/dispensing member 100 doesnot require a cap. In yet another embodiment, the input port 108 may besealed using a sealant as defined herein that is cured after beinginserted into the sealable cavity 110.

Referring to FIGS. 1, 2 and 3A, the herein described fluidaspirating/dispensing member 100 includes a heat sealable cavity 110that is disposed between the sample cavity 106 and the sealable inputport 108. Application of heat to the heat sealable cavity 110 causes thethermoplastic material of the walls to melt and fuse thus sealing thesealable input port 108. Other methods may also be employed to sealinput port 108. For example, a sealant, such as an adhesive, may beapplied to the input port 108 and cured by cooling or other means, forexample, localized exposure to UV radiation. In another version, theinput port 108 is hermetically closed using a bottom cap, for example, abottom screw cap (not shown).

With the foregoing structural description of a fluidaspirating/dispensing member 100, a method is now described with respectto sample collection and particle separation within a fluidaspirating/dispensing member 100 in accordance with a second embodiment.

Referring to FIG. 3B, the fluid aspirating/dispensing member 100 isshown as attached to a metering mechanism 350 and more specifically aproboscis 320 of a clinical analyzer. The proboscis forms a component ofa metering mechanism of the analyzer. Appropriate robotic commandsdirect the metering system to align the proboscis 320 with the inputport 220 of the fluid aspirating/dispensing member 100. After properalignment, the metering system hermetically inserts the proboscis 320through the open input port 220 into the proboscis receptacle region 112of the fluid aspirating/dispensing member 100. The input port 108 isthen immersed into the sample 330. The proboscis 320 of the meteringmechanism 350 creates a controlled amount of negative pressure withinthe internal volume of the fluid aspirating/dispensing member 100. Thesubsequent displacement of air 310 through input port 104 promotes themovement 343 of a defined volume of sample 330 into the sample cavity106 of the fluid aspirating/dispensing member 100. The volume of theaspirated sample depends on the available volume within the samplecavity 106. In one example, an aliquot of between about 1 to about 1000microliters of sample 330 is aspirated. In another example, an aliquotof between about 1 to about 300 microliters of sample 330 is aspirated.In yet another example, from about 1 to about 50 microliters of sample330 is aspirated into the sample cavity 106 of the fluidaspirating/dispensing member 100.

Referring to FIG. 3C, after the aspiration of a sample 330 into thesample cavity 106 is complete, the input port 108 of the fluidaspirating/dispensing member 100 is removed from the sample 330. Theproboscis 320 of the metering mechanism 350 again creates a controlledamount of negative pressure within the internal volume of the fluidaspirating/dispensing member 100 that causes a small bubble of air 347to be aspirated through input port 108 and displaces the aspiratedsample 345 away from the input port 108 and into the sample cavity 106proper. By maintaining the air tight seal between the proboscis 320 andthe proboscis receptacle region 112 of the fluid aspirating/dispensingmember 100, the sample is retained within the sample cavity 106 prior toheat sealing of the input port 108. This procedure ensures both areliable seal and limits any temperature rise of the aspirated sample345 before analysis.

Referring to FIG. 3D, the input port 104 of the fluidaspirating/dispensing member 100 is placed in a heat sealing device 353while the proboscis 320 remains hermetically inserted in the proboscisreceptacle region 112 of the fluid aspirating/dispensing member 100. Thethermoplastic material in the walls of the sealable cavity 110 is thenrapidly heated to its melting temperature. The speed with which thepolymer must be heated to its melt temperature depends on the inherentviscosity of the polymer, the wall thickness and diameter of thesealable cavity 110, as described in detail in U.S. Pat. No. 3,929,943,incorporated herein above. The maximum period for heating can be fromabout 1 to about 30 seconds or from 5 to about 20 seconds or about 10 toabout 15 seconds. The heat sealing device can be a high-intensityradiant heater, such as tungsten or quartz lamp. Alternatively,microwave heaters, such as dielectric heaters or ultrasonic heaters orany other means known in the art can be utilized. The meltingtemperature can be from about 200 degrees to about 350 degrees Celsius,depending on the thermoplastic properties of the fluidaspirating/dispensing member 100. After the walls of the heat sealablecavity 110 are heated, they are pressed in the direction 362 by a press357 to force the walls together and seal the open end. In one version,the end of the press 357 is shaped in the form of a cup 364 that fitsover the input port 108 of the fluid aspirating/dispensing member 100and facilitates the fusion and molding of the input port 108 into asealed end 355. In one version, a metallic press 357 is heated to theappropriate melting temperature and applied directly to the sealableinput port 108. After sealing, the input port 108 is rapidly cooled topromote the solidification of the fused thermoplastic material thusproducing a hermetically sealed fluid container or cuvette. The press357 and metering device 320 are then removed.

Referring to FIGS. 3E-3G, a cap 367 can be inserted over input port 104.The fluid aspirating/dispensing member 360 is then robotically placedinto a fixed angle or swinging bucket rotor of a centrifuge of aclinical analyzer and rotated in the direction 370 around a verticalaxis 365. The port 355 is hermetically sealed and rendered pressureresistant by the heat sealing treatment described above, therebyensuring the aspirated sample 345 remains within the sample cavity 106during centrifugation about the vertical axis 365. As a consequence ofthe centrifugal force acting on the particulate phase of the aspiratedsample 345, particles within the sample accumulate in a pellet 375 atthe bottom of the sample cavity 106 of the fluid aspirating/dispensingmember 100. After centrifugation, the closed cap 367 is removed and thesample supernatant 380 is collected for presentation to either the “wet”and/or “dry” chemistry components of a clinical analyzer.

The sealed fluid aspirating/dispensing member 100, may also be made froma transparent plastic material that permits optical testing of the fluidcontents within the fluid aspirating/dispensing member 100. Detailsrelating to the optical reading of the fluid contents of a sample aredescribed in further detail in U.S. Pat. Nos. 6,013,528 and 5,846,492,the entire contents of each are hereby incorporated by reference. In oneexample, the walls of the fluid aspirating/dispensing member cantransmit electromagnetic radiation of a wavelength required for theexcitation of a fluorescent ligand and electromagnetic radiation of awavelength characteristic of the subsequent emission of fluorescence.

According to another version, the fluid aspirating/dispensing member 100may be preloaded with a separation barrier material, as defined herein,that facilitates the separation of the particulate phase from the liquidphase of a sample during particle separation, for example,centrifugation.

A person of ordinary skill in the art will recognize that the describedembodiments

can be altered in a number of ways and still fall within the intendedscope of the application. For example, the fluid aspirating/dispensingmember 100 described herein can be used as part of a series where asecond fluid aspirating/dispensing member 100 is used to collect thesupernatant 380 of centrifuged sample that was processed in a firstaspirating/dispensing member 100. For example, a sample, such asheparinized blood from a patient, can be aspirated into the samplecavity 106 of a first fluid aspirating/dispensing member 100. After thesealing of the sealable cavity 106, the aliquot is centrifuged to pelletthe blood cells at the bottom of the sample cavity 106. A second fluidaspirating/dispensing member 100 can then be used to aspirate the serumsupernatant 380 into the sample cavity 106 of the second fluidaspirating/dispensing member 100. Sealing of the sealable cavity 110 ofthe second fluid aspirating/dispensing member 100 creates a reactionvessel that can be robotically transported to the wet/dry components ofthe clinical analyzer for additional processing. In one version, thefluid aspirating/dispensing member 100 may be attached to a meteringmechanism 350 having a proboscis 320 that permits pre-loading of thesample cavity with one or more reagents for clinical analysis, forexample, reagents for agglutination , i.e., anti-human immunoglobulin(Coomb's reagent) or other reagents for blood typing. Mixing of thesample with the reagent can be achieved by repeated aspiration anddispensing into a suitable container followed by the aspiration of thehomogenized mixture into the sample cavity 106 of the fluidaspirating/dispensing member 100 for further processing.

It will be readily apparent to one of sufficient skill and as describedin greater detail that the following description is exemplary andtherefore, there is potential to use the fluid aspirating/dispensingmember 100 for the processing of, for example, immunoassays comprisingligand-binding molecules attached to various particles such as latex oragarose beads and the like. A number of ligands are known that bindimmunoglobulin molecules and may be covalently coupled to the particles,for example Protein A, Protein G, Protein A/G, Kappalock. In oneembodiment, the particles may be bound to, for example, bacteriophageexpressing a ligand binding entity (see for example, U.S. Pat. No.6,979,534, the contents of which are hereby incorporated by referenceherein in their entirety).

According to one version, assays used in conjunction with the fluidaspirating/dispensing member 100 may include magnetic particles such asmagnetic beads. Magnetic particles can be aspirated together with asample into the sample cavity 106. After the sealing of the sealablecavity 110, the particles are separated from the rest of the sample asdescribed above by simply deploying a powerful magnet adjacent to thesample cavity in the absence of centrifugation. Many methods are knownin the art where cells can be rendered magnetic for purposes of cellseparation and the like. For example, cells can be incubated withbiotinylated antibodies or other ligand-binding molecules that arespecific for a surface antigen, characteristic of a particular celltype. Addition of streptavidin-conjugated magnetic beads(Invitrogen/Dynal Biotech) then bind to the biotinylated antibodies andthereby render the cells magnetic and hence amenable to cell separationusing a magnetic field. The description of controlled transport ofmagnetic beads is disclosed in U.S. Pat. No. 7,217,561, the contents ofwhich is hereby incorporated herein in its entirety. Cells used in theinvention may also be tagged using labeled antibodies known in the art.For example, the labeled antibodies may be fluorophore-conjugatedantibodies. Agglutination can be monitored by the detection offluorescence emitted from agglutinated cells.

In accordance with a third embodiment, FIGS. 4A and 4B illustrate afluid aspirating/dispensing member assembly configuration that is moreamenable to automation and high throughput analysis of a plurality ofsamples. FIG. 4A depicts a fluid aspirating/dispensing plate 400 onwhich 96 of the fluid aspirating/dispensing members 100 of FIG. 1 arearranged into 8 rows of 12 fluid aspirating/dispensing members 425. FIG.4B portrays a cross sectional view of the plate 400 to show row 420 of12 fluid aspirating/dispensing members 425 attached to a solid support414. In one version, the attachment may be reversible. Each of theaspirating/dispensing members 425 comprises an input port 404, proboscisreceptacle region 412 attached to a solid support 414, a sample cavity406, a sealable cavity 410 and sealable input port 408. FIG. 5illustrates how the sealable input ports 408 of the fluidaspirating/dispensing plate 400 can align with the wells 510 of amicrotiter plate 500.

With the foregoing structural description of a fluidaspirating/dispensing plate 400 of fluid aspirating/dispensing members,a method is now described with respect to sample collection and particleseparation using a fluid aspirating/dispensing plate 400 in accordancewith a fourth embodiment.

Referring to FIGS. 6A, a cross section view of the row 420 of the fluidaspirating/dispensing members 425 of FIG. 4B is portrayed with thesealable input ports 408 aligned with the wells 510 of a microtiterplate 500. Appropriate robotic commands direct the metering mechanism603 to align the proboscises 605 with the input ports 404 of the fluidaspirating/dispensing plate 400. After proper alignment, the meteringsystem hermetically inserts the proboscises 605 through the open inputports 404 into the proboscis receptacle regions 412 of the fluidaspirating/dispensing members 425.

Referring to FIGS. 6B and 6C, the metering mechanism then aligns thesealable input ports 408 of the fluid aspirating/dispensing members 425with the wells 510 of the microtiter plate 500 and immerses the sealableinput ports 408 into the samples 607 within each well 510. Theproboscises 605 of the metering mechanism 603 create a controlled amountof negative pressure within the internal volume of each of the fluidaspirating/dispensing members 425. The subsequent displacement of air601 through the input ports 404 promotes the movement 643 of a definedvolume of samples 607 into the sample cavities 406 of each of the fluidaspirating/dispensing members 425. The volume of the aspirated samplewithin each fluid aspirating/dispensing member 425 depends on theavailable volume within the sample cavities 406. In one example, analiquot of between 0.1 to 1000 microliters of sample 607 is aspirated.In another example, an aliquot of between 0.1 to 300 microliters ofsample 607 is aspirated. In yet another example, from 0.1 to 50microliters of sample 607 is aspirated into the sample cavity 406 ofeach of the fluid aspirating/dispensing members 425.

Referring now to FIG. 6D, the sealable input ports 408 are removed fromthe samples 607 in the wells 510. Again the proboscises 605 of themetering mechanism 603 exert a controlled amount of negative pressurewithin the internal volume of each of the fluid aspirating/dispensingmembers 425. The subsequent displacement of air within the internalcavities of the row 420 of fluid aspirating/dispensing members in thedirection 625 causes the movement of the aspirated sample 620 into thesample cavity 406 proper and the aspiration of a measured amount of air610 through the sealable input ports 408 into the sealable cavity 410prior to heat sealing of the sealable input ports 408. This procedureaverts the heating of the aspirated sample 620 and ensures a reliableseal.

As shown in FIG. 6E, the walls of the sealable cavities 410 are thenheated to the appropriate melting temperature using the row of heatsealing devices 640. After the walls of the heat sealable cavities 410are heated, they are pressed in the direction 635 by the presses 630 toforce the walls together and seal the open ends of the sealable inputports 408. In one version, the ends of the presses 630 are shaped in theform of a cup 645 that fits over the sealable input ports 408, therebyfacilitating the fusion and molding of the input ports 408 into thesealed ends 650, depicted in FIG. 6F. In one version, metallic presses630 are heated to the appropriate melting temperature and applieddirectly to the sealable input ports 408 for the melting and fusion ofthe walls of the sealable cavities 410. After sealing, the sealableinput ports 408 are rapidly cooled to promote the solidification of thefused thermoplastic material thus producing a hermetically sealed fluidcontainer or cuvette. The presses 630 and the proboscises 605 are thenremoved.

Referring to FIG. 6G-I, an optional lid 660 is placed onto the fluidaspirating/dispensing plate 400 and hermetically seals the input ports404 of the fluid aspirating/dispensing members. Lid 660 prevents theaspirated sample 620 from escaping the sample cavity 406 of each fluidaspirating/dispensing member and prevents cross-contamination of theaspirated samples 620. The fluid aspirating/dispensing plate 400 is thenrobotically placed into a fixed angle or swinging bucket rotor of acentrifuge and spun around a vertical axis 365 in the direction 370 forthe time required to separate the particles within the aspirated samplefrom the rest of the sample. At the conclusion of the centrifugation,the particles within the aspirated samples 620 form pellets 670 at thebottom of the sample cavities 406. The lid 660 is then removed and thesupernatants 680 can be collected and presented to the wet/drycomponents of the clinical analyzer.

In an alternative version, the sample cavities 406 may be preloaded witha separation barrier material, as defined herein, to facilitate theseparation of the particulate phase from the liquid phase of theaspirated samples 620 during centrifugation. In another version, thesample cavities 406 may be pre-loaded with reagents, for example,reagents for agglutination or blood typing or antibodies attached tovarious particles as defined herein for immunoassays. In yet anotherversion, the aspirated samples 620 within the fluidaspirating/dispensing members of a plate contain magnetic particles thatcan be separated from the rest of the aspirated samples 620 by placingthe plate on a strong magnet according to protocols that are well knownin the art.

As noted above, the herein described processing of samples in a plate offluid aspirating/dispensing members is particularly amenable toautomation for the rapid processing of STAT samples in urgent carefacilities. Sample processing can be controlled by appropriate softwareprograms running on a dedicated computer component of a , clinicalanalyzer. In one version, the solid support 414 of a plate of fluidaspirating/dispensing members further comprises appendages to facilitaterobotic handling and appropriate adapters for centrifugation.

The disclosure herein also provides for a kit format which comprises apackage unit having one or more fluid aspirating/dispensing members ofthe subject disclosure and in some embodiments includes containers ofvarious reagents. The kit may also contain one or more of the followingitems: buffers, instructions, and positive or negative controls. Kitsmay include containers of reagents mixed together in suitableproportions for performing the methods described herein. Reagentcontainers preferably contain reagents in unit quantities that obviatemeasuring steps when performing the subject methods. Kits may furthercomprise fluid aspirating/dispensing members pre-loaded with reagents.

PARTS LIST FOR FIGS. 1-6I

-   100 fluid aspirating/dispensing member-   104 input port-   106 sample cavity-   108 sealable input port-   110 heat sealable cavity-   112 proboscis receptacle region-   114 cap-   116 connector-   118 vertical axis-   210 movement of cap-   220 open input port-   225 closed input port-   310 direction of movement of air-   320 proboscis-   330 sample-   335 direction of movement of sample-   343 aspiration of sample-   345 aspirated sample-   347 air space-   350 metering mechanism-   353 heat sealing device-   355 sealed end-   357 press-   360 fluid aspirating/dispensing member in a centrifuge-   362 direction of movement of press-   364 cup-   365 axis of rotation-   367 closed cap-   370 direction of rotation-   375 pellet-   380 supernatant-   390 probe-   400 Fluid aspirating/dispensing plate with array of fluid    aspirating/dispensing members-   404 input ports-   406 sample cavities-   408 sealable input ports-   410 sealable cavities-   412 proboscis receptacle regions-   414 solid support-   420 row of fluid aspirating/dispensing members-   425 fluid aspirating/dispensing member-   500 microtiter plate-   510 wells-   601 direction of movement of air-   603 array of metering mechanisms-   605 array of proboscises-   607 samples-   610 aspiration of air-   615 array of probes-   620 aspirated samples-   625 direction of movement of air-   630 presses-   640 heat sealer devices-   643 aspiration of samples-   645 cup-   650 sealed ends-   660 cover-   670 pellets-   680 supernatants

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the intended scope of the inventionencompassed by the following appended claims.

1. A method of configuring a metering tip for use as a microcentrifugetube in a clinical analyzer, said method comprising the steps of: a)providing a metering tip, said metering tip comprising an upper port, anopposing lower port and a sample cavity in fluid communication with eachof said upper and lower ports; b) attaching said metering tip to aproboscis of said analyzer, said proboscis being heremetically sealed tothe upper port; c) aspirating a fluid sample from a sample supply insaid analyzer into said sample cavity through said lower port of saidmetering tip; d) aspirating a volume of air with said aspirated sample,said volume of air being aspirated into said tip through said lower portfollowing the fluid sample aspiration step and providing an insulatinglayer between said sample and the lower port; e) sealing said lower portof said metering tip in order to create a fluid container; f) removingsaid proboscis and closing said upper port using a cap sized toreleasably engage and cover said upper port; and g) separating particlesin said fluid sample from the remainder of said fluid sample, whereinthe separated particles and sample are retained within said samplecavity of said metering tip for detection of particles.
 2. The method ofclaim 1, wherein the separating step is performed by centrifugation. 3.The method of claim 1, wherein the sealing step is performed using byheat-sealing the lower port of said metering tip.
 4. The method of claim1, wherein said cap is tethered to the upper port.
 5. A method ofseparating particles in a plurality of fluid samples, said methodcomprising the steps of: a) loading a plurality of fluidaspirating/dispensing members into a supporting plate having a pluralityof openings, said openings being sized for receiving a correspondingnumber of fluid aspirating/dispensing members, each of said fluidaspirating/dispensing members comprising an upper port, an opposinglower port and a sample cavity in fluid communication with each of saidupper and lower ports; b) aspirating a plurality of samples into saidsample cavities through said lower ports of each of said fluidaspirating/dispensing members; c) sealing the lower ports of each ofsaid fluid aspirating/dispensing members to create a plurality of fluidcontainers; and d) separating particles in said sample from theremainder of the sample in each of said containers, wherein theseparated particles and sample are retained within said sample cavity ofeach of said fluid aspirating/dispensing members for detection of theparticles or sample.
 6. The method of claim 5, wherein said supportingplate includes a linear array of openings for simultaneously retaining alinear array of fluid aspirating/dispensing members.
 7. The method ofclaim 5, wherein said supporting plate includes a two-dimensional arrayof openings for simultaneously retaining a two-dimensional array offluid aspirating/dispensing members.
 8. The method of claim 5, whereinsaid loading step requires the attachment of said fluidaspirating/dispensing plate to a plurality of proboscises, saidproboscises being part of a metering mechanism of said testingapparatus.
 9. The method of claim 5, wherein said fluidaspirating/dispensing members are metering tips.
 10. The method of claim5, wherein said testing apparatus is a clinical analyzer.
 11. The methodof claim 5, wherein the separating step is performed by centrifugation.12. The method of claim 5, further comprising a step, following saidaspirating step, wherein the upper ports of each of said fluidaspirating/dispensing members are closed by a lid.
 13. The method ofclaim 5, wherein the sealing step is performed by heat sealing saidsecond ports of each of said members.
 14. The method of claim 5, whereinsaid aspirating step includes the additional step of aspirating a volumeof air between said sample cavity and said lower port of each of saidfluid aspirating/dispensing members prior to sealing said lower port.